Simplify the following expression: ${4z-(9z-3)}$
Answer: The minus sign in front of the parentheses means we multiply each term inside the parentheses by ${-1}$ $ 4z {-1(}\gray{9z-3}{)} $ $ 4z {-9z+3} $ Combine the $z$ terms: $ {4z - 9z} + 3$ $ {-5z} + 3$ The simplified expression is $-5z+3$